Heterosis is the phenomenon that the hybrid offspring outperform two-parent population. Hybridisation has been widely used in plant and animal production as it effectively improves the growth and developmental performance, reproductive performance and disease resistance of the offspring. Hybridization can effectively improve the growth and development performance, reproductive performance and disease resistance of offspring, so it is widely used in animal and plant production. Researchers have used cross-breeding techniques to cultivate excellent new agricultural and animal husbandry strains and supporting lines such as super-excellent Chaoyou 1000 hybrid rice, Xiaoyan No.6 hybrid wheat, Dumeng sheep, and Shanxia black pigs. However, there are still some urgent problems in the current hybrid dominance research: the existing hybrid dominance theory can only partially explain the phenomenon of plant and animal hybrid dominance, and the theory of animal hybrid dominance is less researched, and the accuracy of the existing hybrid dominance prediction methods is limited. China is the world\'s largest pork production and consumption country. Heterosis can effectively improve the production performance of pigs, and its application in the pig industry has important economic and research value. However, the existing research on pig hybrid production is in its infancy and needs to be further studied. In this review, we summarize the existing heterosis theory, heterosis prediction methods, and their application in pig production, to provide a reference for the application of heterosis in pig breeding.
杂种优势是指杂种后代的性能优于双亲群体的现象。杂交能有效提高后代的生长发育性能、繁殖性能和抗病性，因此被广泛应用于动植物生产。研究人员利用杂交育种技术培育了超优千号杂交水稻、小偃6号杂交小麦、杜蒙羊、山下黑猪等优秀的农牧新品系和配套系。然而当前的杂种优势研究仍存在一些亟待解决的问题：现有杂种优势理论只能部分解释动植物杂种优势现象，动物杂种优势理论研究较少，且现有的杂种优势预测方法准确性有限。我国是世界上最大的猪肉生产消费国，杂种优势能够有效提高生猪生产性能，在生猪产业的应用方面具有重要的经济和研究价值。但目前有关猪杂交生产研究还处于起步阶段，亟待进一步深入。本文综述了现有的杂种优势理论、杂种优势预测方法，及其在猪生产中的应用研究，以期为杂种优势在生猪育种中的应用提供借鉴与参考。.

The flavour, tenderness and juiciness of the beef are all impacted by the composition of the intramuscular fat (IMF), which is a key determinant of beef quality. Thus, enhancing the IMF composition of beef cattle has become a major area of research. Consequently, the aim of this paper was to provide insight and synthesis into the emerging technologies, nutritional practices and management strategies to improve IMF composition in beef cattle. This review paper examined the current knowledge of management techniques and nutritional approaches relevant to cattle farming in the beef industry. It includes a thorough investigation of animal handling, weaning age, castration, breed selection, sex determination, environmental factors, grazing methods, slaughter weight and age. Additionally, it rigorously explored dietary energy levels and optimization of fatty acid profiles, as well as the use of feed additives and hormone implant techniques with their associated regulations. The paper also delved into emerging technologies that are shaping future beef production, such as genomic selection methods, genome editing techniques, epigenomic analyses, microbiome manipulation strategies, transcriptomic profiling approaches and metabolomics analyses. In conclusion, a holistic approach combining genomic, nutritional and management strategies is imperative for achieving targeted IMF content and ensuring high-quality beef production.

Mosquitoes (Diptera: Culicidae) are one of the most studied groups of arthropods worldwide due to their high transmission capacity for pathogens, including viruses and parasites. During June to October 2022, the prevalence of mosquito species in 12 intensive pig farms from 12 representative administrative regions in Hunan province of China was investigated using traps with ultraviolet light. All collected mosquitoes were counted and identified to species according to morphological and molecular methods. A total of 4,443 mosquito specimens were collected in the pig farms, and they represented one family, four genera and nine species. Culex pipiens pipiens (24%) was the most common mosquito species, followed by Armigeres subalbatus (23.4%) and Culex tritaeniorhynchus (20.6%). Phylogenetic analyses based on mitochondrial cox1 sequences revealed all mosquito species from present study grouping into distinct monophyletic groups corresponding to nine known mosquito species with strongly supported. The results of the present investigation have implications for the ongoing control of mosquito infestation in pig farms in Hunan province, China. This is the first report of mosquito populations in intensive pig farms in Hunan province, China.

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The excessive use of antibiotics, disinfectants, and drugs in livestock and poultry breeding has resulted in a rise in the presence of antibiotic resistance genes (ARGs). Antibiotic-resistant bacteria (ARB) and ARGs have been widely found in animal feces, farm wastewater, and farm air. ARGs can not only spread across media through adsorption and migration, but also transfer resistance across bacterial genera through horizontal gene transfer. Livestock breeding has become a fixed and unavoidable source of ARGs in the environment. Existing technologies for controlling ARGs, such as composting, disinfection, and sewage treatment, are not efficient in removing ARB and ARGs from waste. Furthermore, the remaining ARGs still possess a strong capacity for dissemination. At present, antibiotics used in animal husbandry are difficult to replace in a short period of time. The growth and potential risks of resistance genes in livestock and poultry breeding sources in the receiving environment are not yet clear. In this paper, we summarize the current situation of ARGs in the livestock and poultry breeding environment. We also explain the key environmental processes, main influencing factors, and corresponding ecological risks associated with ARGs in this environment. The advantages and disadvantages of current technologies for the removal of ARGs are primarily discussed. There is a particular emphasis on clarifying the spatiotemporal evolution patterns and environmental process mechanisms of ARGs, as well as highlighting the importance and urgency of developing efficient pollution control technologies.

China\'s poultry industry faces challenges in adopting and sustaining cage-free systems for poultry production. Effective interventions are crucial to support producers transitioning from cages to alternative systems or maintaining cage-free systems to improve animal welfare. However, little is known about how Chinese poultry producers perceive animal welfare in relation to cage-free systems and the importance of animal welfare in poultry production. Through a qualitative interview study with 30 Chinese farm owners, managers and senior managers from large-scale egg and broiler farms using cages and non-cage systems (collectively referred to as \"producers\"), this paper explores Chinese poultry producers\' attitudes and perceptions regarding animal welfare and welfare in different poultry housing systems. Template analysis was used to analyse the data from semi-structured interviews, which generated themes related to the participants\' awareness and understanding of the concept of animal welfare, the factors that impacted their choices of different housing systems, and the perceived priorities in poultry production. The responses revealed that the participating producers had a strong awareness and knowledge of animal welfare. However, the participants\' understanding of the term is heterogeneous: generally, egg producers emphasised natural behaviours, whereas broiler producers prioritised health and productivity. Nevertheless, profitability, leadership, and organisational policies primarily influenced housing system choices rather than animal welfare values. Economic motives drove egg producers towards cage-free systems, prompted by consumers\' and companies\' demand for cage-free eggs committed to transitioning away from cages by 2025. In conclusion, tailored interventions for different poultry sectors within China are necessary. While animal welfare values matter, economic incentives seem more promising for steering the shift towards and maintaining cage-free poultry production.

The mitigation of methane (CH4) emissions from livestock production is crucial to China\'s carbon neutrality. Here we established a high-spatiotemporal-resolution dataset of the country\'s livestock CH4 emissions from 1990 to 2020 using four large-scale national livestock greenhouse gas inventory surveys. We estimate CH4 emissions to be 14.1 ± 2.0 Mt in 2020 and to increase by 13% until 2030 despite CH4 intensity per kg animal protein having decreased by 55% in the past 30 years. Approximately half of the emissions come from 13% of all Chinese counties. The technical CH4 mitigation potential is projected to be 36 ± 8% (4.4-6.9 Mt CH4) in 2030, and reducing food loss and waste could mitigate an additional 1.6 Mt of CH4. Overall, most CH4 mitigation could be achieved by increasing animal productivity and coverage of lagoon storage at carbon prices below US$100 tCO2e-1, being more cost-effective than livestock nitrous oxide mitigation in China.

Realizing the market value of grassland resources is of great significance to finding a balance between ecological protection and economic development. As a unique livestock animal that is native to the Qinghai-Xizang Plateau, the yak plays an important role in maintaining ecosystem stability, ensuring the livelihoods of herdsmen, promoting socio-economic development, and preserving ethnic cultural traditions. However, given its small market share, little is known about the factors that drive Chinese consumer preferences for yak meat. This study aimed to investigate consumer preferences for yak meat by means of an online survey involving a sample of 2999 respondents from five cities in China. The best-worst scaling method was employed to measure the relative importance of different attributes of yak meat by using a purchasing scenario. The results indicated that quality-safety certification, freshness, and production sustainability were regarded as the most preferred attributes, whereas animal welfare, brand, and the purchasing channel were found to be the least preferred. In addition, significant heterogeneity was detected in consumer preferences. Consumers were divided into three classes, namely \'Price Sensitive Consumers,\' \'Environmentally Friendly Consumers,\' and \'Yak Meat Inclined Consumers,\' respectively. Our findings might be helpful for policymakers and yak meat producers to develop targeted strategies to facilitate the sale of yak meat and then restore degraded grasslands.

Livestock and poultry products are an essential human food source. However, the rapid development of the livestock sector (LS) has caused it to become a significant source of greenhouse gas (GHG) emissions. Consequently, investigating the spatio-temporal characteristics and evolution of GHG emissions is crucial to facilitate the green development of the LS and achieve \"peak carbon and carbon neutrality\". This study combined life cycle assessment (LCA) with the IPCC Tier II method to construct a novel GHG emissions inventory. The GHG emissions of 31 provinces in China from 2000 to 2021 were calculated, and their spatio-temporal characteristics were revealed. Then, the stochastic impacts by regression on population, affluence, and technology (STIRPAT) model was used to identify the main driving factors of GHG emissions in six regions of China and explore the emission reduction potential. The results showed that GHG emissions increased and then decreased from 2000 to 2021, following a gradual and steady trend. The peak of 628.55 Mt CO2-eq was reached in 2006. The main GHG-producing segments were enteric fermentation, slaughtering and processing, and manure management, accounting for 45.39 %, 26.34 %, and 23.08 % of total GHG emissions, respectively. Overall, the center of gravity of GHG emissions in China migrated northward, with spatial aggregation observed since 2016. The high emission intensity regions were mainly located west of the \"Hu Huanyong line\". Economic efficiency and emissions intensity were the main drivers of GHG emissions. Under the baseline scenario, GHG emissions are not projected to peak until 2050. Therefore, urgent action is needed to promote the low-carbon green development of the LS in China. The results can serve as scientific references for the macro-prevention and control of GHG emissions, aiding strategic decision-making. Additionally, they can provide new ideas for GHG accounting in China and other countries around the world.

Alpine grasslands are distributed widely on high-elevated ranges and plateaus from the wet tropics to polar regions, accounting for approximately 3% of the world\'s land area. The Qinghai-Tibetan Plateau (QTP) is the highest and largest plateau in the world, and approximately 60% of the plateau consists of alpine grassland, which is used mainly for grazing animals. Livestock structure was determined in Guinan (GN), Yushu (YS) and Maqu counties (MQ) on the QTP by interviewing 235 local pastoralists. Based on data collected from GN, the livestock carrying capacity was calculated using herbage dry matter biomass intake (LCCm) by the livestock, and the metabolizable energy yield (LCCe) and digestible crude protein (LCCp) available in pasture. The pasture area per household differed among the regions of the QTP, which was the main reason for the difference in livestock stocking rate. The householders raised the appropriate proportion of breeding females and young yaks and sheep in GN and MQ, but not in YS, to maintain a constant turnover. Most pasture in YS was used at the community level, especially in summer. The calculated carrying capacities based on metabolizable energy yield (LCCe) of the pasture and dry matter biomass (LCCm) were similar in most months except for August, when the value of LCCe was higher than LCCm. Based on the digestible protein of the pasture, the calculated livestock carrying capacity overestimated the actual carrying capacity during the herbage growing season from May to September. Appropriate practices should be taken in different regions of QTP, such as providing supplementary feed, especially protein, during the forage non-growing season. Livestock carrying capacity should be adjusted dynamically, and calculated by a number of parameters. The stocking rate should be controlled to optimize livestock production and curb or minimize grassland degradation to generate a sustainable system. This study examined the grasslands and LCC on the QTP, but the results could be applied to grasslands worldwide.